现在使用.net老是感觉.net自带的控件的很多的功能不尽人意,所以参考微软的学习资料,感觉自己编一个符合自己要求的Control还是很简单的
HOW TO: Create a Smooth Progress Bar in Visual C# .NET就是叫我们怎么样做自己的控件的
其实做好其中的几个重要函数的重写工作就可以了
例如OnResize(),OnPaint()
protected override void OnPaint(PaintEventArgs e) { Graphics g = e.Graphics; SolidBrush brush = new SolidBrush(BarColor); float percent = (float)(val - min) / (float)(max - min); Rectangle rect = this.ClientRectangle;
// Calculate area for drawing the progress. rect.Width = (int)((float)rect.Width * percent);
// Draw the progress meter. g.FillRectangle(brush, rect);
// Draw a three-dimensional border around the control. Draw3DBorder(g);
// Clean up. brush.Dispose(); g.Dispose(); } private void Draw3DBorder(Graphics g) { int PenWidth = (int)Pens.White.Width;
g.DrawLine(Pens.DarkGray, new Point(this.ClientRectangle.Left, this.ClientRectangle.Top), new Point(this.ClientRectangle.Width - PenWidth, this.ClientRectangle.Top)); g.DrawLine(Pens.DarkGray, new Point(this.ClientRectangle.Left, this.ClientRectangle.Top), new Point(this.ClientRectangle.Left, this.ClientRectangle.Height - PenWidth)); g.DrawLine(Pens.White, new Point(this.ClientRectangle.Left, this.ClientRectangle.Height - PenWidth), new Point(this.ClientRectangle.Width - PenWidth, this.ClientRectangle.Height - PenWidth)); g.DrawLine(Pens.White, new Point(this.ClientRectangle.Width - PenWidth, this.ClientRectangle.Top), new Point(this.ClientRectangle.Width - PenWidth, this.ClientRectangle.Height - PenWidth)); } 这一段程序就是自己绘制控件外观的,很简单吧
可以自己添加控件的事件,特性(property),方法
public int Minimum { get { return min; }
set { // Prevent a negative value. if (value < 0) { min = 0; } // Make sure that the minimum value is never set higher than the maximum value. if (value > max) { min = value; min = value; } // Ensure value is still in range if (val < min) { val = min; }
// Invalidate the control to get a repaint. this.Invalidate(); } }
public int Maximum { get { return max; }
set { // Make sure that the maximum value is never set lower than the minimum value. if (value < min) { min = value; }
max = value;
// Make sure that value is still in range. if (val > max) { val = max; }
// Invalidate the control to get a repaint. this.Invalidate(); } }
public int Value { get { return val; }
set { int oldValue = val;
// Make sure that the value does not stray outside the valid range. if (value < min) { val = min; } else if (value > max) { val = max; } else { val = value; }
// Invalidate only the changed area. float percent;
Rectangle newValueRect = this.ClientRectangle; Rectangle oldValueRect = this.ClientRectangle;
// Use a new value to calculate the rectangle for progress. percent = (float)(val - min) / (float)(max - min); newValueRect.Width = (int)((float)newValueRect.Width * percent);
// Use an old value to calculate the rectangle for progress. percent = (float)(oldValue - min) / (float)(max - min); oldValueRect.Width = (int)((float)oldValueRect.Width * percent);
Rectangle updateRect = new Rectangle(); // Find only the part of the screen that must be updated. if (newValueRect.Width > oldValueRect.Width) { updateRect.X = oldValueRect.Size.Width; updateRect.Width = newValueRect.Width - oldValueRect.Width; } else { updateRect.X = newValueRect.Size.Width; updateRect.Width = oldValueRect.Width - newValueRect.Width; }
updateRect.Height = this.Height;
// Invalidate the intersection region only. this.Invalidate(updateRect);//注意这是强制重绘的,一定要有,不然图形不会改变的^_^ } }
public Color ProgressBarColor//控制颜色的 { get { return BarColor; }
set { BarColor = value;
// Invalidate the control to get a repaint. this.Invalidate(); } } 这是自己添加的特性(property)
虽然这是一个很小的示例,但是向我们这种菜鸟展示的.net的强大.通过这种方式我们完全可以做到开发符合自己要求的控件.
程序来自微软网站 
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